Combined electrophoretic and immunochemical procedures have been standardized and applied for the determination of proteins in paired serum and CSF samples to aid the diagnosis of neurologic diseases (1). Demonstration of oligoclonal immunoglobulins in CSF samples from patients with post-poliomyelitis muscular atrophy contributed useful information on the immunological mechanism operating in the pathogenesis of this disease (2). Detection and identification of monoclonal immunoglobulins in serum and urine samples from patients with Sjogren's syndrome aided diagnosis and differentiation of these patients into glandular and extraglandural categories (3). Analysis of serum samples from AIDS patients, demonstrated for the first time a high incidence of oligoclonal immunoglobulins in AIDS patients with Kaposi's sarcoma compared to a low incidence in those with opportunistic infections only. This demonstration and differentiation aids diagnosis and treatment of AIDS patients (4).